Battery packs provide power for various technologies ranging from portable electronics to renewable power systems and environmentally friendly vehicles. For example, hybrid electric vehicles (HEV) use a battery pack and an electric motor in conjunction with a combustion engine to increase fuel efficiency. Battery packs can be formed of a plurality of battery modules, where each battery module includes several electrochemical cells. Within the battery modules, the cells are arranged in two or three dimensional arrays and are electrically connected in series and/or in parallel. Likewise, the battery modules within a battery pack are electrically connected in series and/or in parallel.
Different cell types have emerged in order to deal with the space requirements of a Very wide variety of installation situations, and the most common types, used in automobiles are cylindrical cells, prismatic cells, and pouch cells. Regardless of cell type, each cell may include a cell housing and an electrode assembly disposed in the cell housing. The electrode assembly includes an alternating series of stacked or rolled positive electrode plates and negative electrode plates that are separated by an intermediate separator material. A liquid electrolyte sealed within the cell housing infiltrates the electrode assembly. Each cell may also include a positive terminal that is electrically connected to the positive electrode plates and protrudes outside the cell housing via a first sealed hole in the cell housing, and a negative terminal that is electrically connected to the negative electrode plates and protrudes outside the cell housing via a second sealed hole in the cell housing.
There are technical challenges associated with providing a reliable seal around the terminals as the terminals exit the cell housing. When the cell housing is electrically conductive and the terminals are required to be electrically isolated from the cell housing, further challenges are presented. Although some electrochemical cells include terminal assemblies that address these challenges, the solutions tend to be complex in that they include many parts and thus are complex and costly to manufacture and assemble. A need exists for a terminal assembly that addresses the challenges described above, and that is simple, easily manufactured, and can be produced at a low cost.